What does the MD5 algorithm do?
A.
takes a message less than 2^64 bits as input and produces a 160-bit message digest
B.
takes a variable-length message and produces a 168-bit message digest
C.
takes a variable-length message and produces a 128-bit message digest
D.
takes a fixed-length message and produces a 128-bit message digest
Explanation:
http://www.cisco.com/en/US/tech/tk583/tk372/technologies_tech_note09186a0080094203.shtml
Message Digest 5 (MD5)—This is a one way hashing algorithm that produces a 128-bit hash. Both
MD5 and Secure Hash Algorithm (SHA) are variations on MD4, which is designed to strengthen
the security of this hashing algorithm. SHA is more secure than MD4 and MD5. Cisco uses hashes
for authentication within the IPsec framework.